For packages such as GCC, that of course will take a lot of time. For Java, there are other supported runtimes like Azul Zulu, but Homebrew just wants OpenJDK and not much else.
Besides being used internally as mentioned, making the Alpha Geeks (to use Tim O'Reilly's phrase) happy would be prudent for their continued success. If the Alpha Geeks aren't using your product, they will not recommended it to their friends when asked for computer advise, and it will not be installed in relatives' home where the Alpha Geeks tend to do tech support.
The Alpha Geeks was how Apple probably got more popular that PCs in the first place, and they may now have a lot/enough inertial to keep moving forward, but Microsoft and PCs used to be the 800-pound (400 kg) gorilla, and they're less so now.
There's a lot of Unix-y stuff being used in academy, research, and HPC: plenty of folks there would be just as willing to switch to a PC with Ubuntu/Debian/CentOS (which run the world's HPC clusters) if macOS gets in the way of their workflow if Homebrew or Macports don't work.
At which point in time was that?
From the statistics I could google in a few seconds, for the last 20 years, MacOS was always hovering around 10-15% of the worldwide desktop PC market share with Windows at around 75-85% and linux/BSD the rest of the scraps.
Absolutely. I'd say Linux is the default for science and ML!
If Microsoft is less successful in the home market now, it is because Windows is seen by many consumers as too techy, and too difficult.
You may say that's not true. But just look at their actions and not their marketing speak.
There is essentially no regression, and Apple is donating hardware to enable Homebrew to do the work to extract more performance from the new chips.
What ‘more’ do you think they should do?
This is classic of the all or nothing attitude that anti-Apple and anti-Mac people have. Unless Apple does some Herculean task that shows they're worthy, they're shit.
That makes the process much more complex.
They haven’t impacted homebrew users negatively at all.
People have been consistently rewarding them for this direction by buying more of their stuff and relying on open source projects to fill in the gaps without really acknowledging the obvious problem that Apple has made it increasingly unattractive to use their hardware to do anything other than Apple stuff.
To me it matters most that I be able to do things that I want easily on the platform I choose - in that sense PC hardware with Linux is the best choice I have, with Windows coming in 2nd due to how much Microsoft has done to make their OS attractive for wide variety of use cases that are not necessarily to Microsoft's direct benefit.